D, the theory has been built up with evidence over time.
I can answer number 3. Osmosis is a unique property of water that allows water to move past cell walls. Like when water evaporates out of your plastic cup.
The answer is missense. Hope this helps!
A. Scientific ideas are changed when better ones are found.
Gastrulation marks the beginning of germ layer development in an embryo.A germ layer is a group of cells in an embryo that interact with each other as the embryo develops and contribute to the formation of all organs and tissues. The germ layers develop early in embryonic life, through the process of gastrulation.
